Nulls can't exist in HCL, and the legacy sdk will panic when
encountering them. The map shim already did this, just copy the same
pattern in the list case.
In order to preserve pre-v0.12 idiom for list-of-object attributes, we'll
prefer to use block syntax for them except for the special situation where
the user explicitly assigns an empty list, where attribute syntax is
required in order to allow existing provider logic to differentiate from
an implicit lack of blocks.
It turns out that collections containing only unknowns could be lost,
meaning there wasn't a direct correlation between the unknown and null
value which would have otherwise been restored.
The legacy diff process inserts unknown values into an optional+computed
map. Fix these up in post-plan normalization process, by looking for
known strings that were changed to unknown.
Because schema.ResourceDiff can't differentiate between unknown
values and new computed values, unknowns can be lost during an update.
If a planned value converted an unknown to a null, restore the unknown
so that it can be correctly replaced in the final plan.
* configs/configupgrade: detect invalid resource names and print a TODO
message
In terraform 0.11 and prior it was possible to start a resource name
with a number. This is no longer valid, as the resource name would would
be ambiguous with number values in HCL expressions.
Fixes#19919
* Update configs/configupgrade/test-fixtures/valid/invalid-resource-name/want/resource.tf
Co-Authored-By: mildwonkey <mildwonkey@users.noreply.github.com>
For compatibility with documented patterns from existing providers we are
now allowing (via a pre-processing step) any attribute whose type is a
list-of-object or set-of-object type to optionally be assigned using one
or more blocks whose type is the attribute name.
The pre-processing functionality was implemented in previous commits but
we were not correctly detecting references within these blocks that are,
from the perspective of the primary schema, invalid. Now we'll use an
alternative implementation of variable detection that is able to apply the
same schema rewriting technique we used to implement the transform and
thus can find all of the references as if they were already in their
final locations.
Because we handle FixUpBlockAttrs after dynamic block expansion, when
resolving variables we unfortunately need to consider the possibility of
both dynamic block expansion _and_ the block attrs fixup.
To accommodate this we have a variant of dynblock.VariablesHCLDec that
instead walks using the configschema.Block representation of the schema
and applies the same opportunistic schema rewrite used by FixUpBlockAttrs
at each body encountered during the walk.
This gives us an extra hook in the dynblock variables analysis that should
allow us to also make it subject also to the lang/blocktoattr fixup, to
ensure we'll find all the references in spite of these various
pre-processing wrappers.
For any block content we evaluate dynamically via this API, we'll make a
special allowance for users to optionally write members of a list
attribute instead as a sequence of nested blocks, thus allowing some
existing provider features that were assuming this capability to continue
to support it after v0.12.
This should not be used for any new provider features, and should ideally
be eventually phased out so that there aren't two
similar-but-slightly-different syntaxes for saying the same thing.
This preprocessing step allows users to use nested block syntax to specify
elements of an attribute that is defined as being a list or set of an
object type.
This restores part of the unintended flexibility permitted in Terraform
v0.11 so that we can work around a few tricky edges where provider
implementations were relying on Terraform's failure to validate this in
earlier versions.
For any body that is pre-processed using this new helper, we will
recognize when a configuration author uses nested block syntax with a
name that is specified in the schema as an attribute of a suitable type
and tweak the schema just in time before decoding to expect that usage
and then fix up the result on the way out to conform to the original
schema.
Achieving this requires an abstraction inversion because only Terraform's
high-level schema has enough information to decide how to rewrite the
incoming low-level schema. We must therefore here implement HCL's
lowest-level API interface in terms of the higher-level abstractions of
hcldec and Terraform's configschema.
Because of the abstraction inversion this fixup mechanism cannot be used
generally for arbitrary HCL bodies but we can use it carefully inside the
lang package where its own API can guarantee the necessary invariants for
this to work.
If the registry is unresponsive, you will now get an error
specific to this, rather than a misleading "provider unavailable" type
error. Also adds debug logging for when errors like this may occur
When failing to write the state, the local backend writes the state to a local file called `errrored.tfstate`. Previously it would do so by creating a new state file which would use a new serial and lineage. By exorting the existing state file and directly assigning the new state, the serial and lineage are preserved.
Some users are not accustomed to thinking of IP addresses in a bitwise
fashion, so the hope here is to give enough of an introduction to that way
of thinking for the reader to understand what the "newbits" and "netnum"
arguments represent.
The definition of split was referring the built-in function join. However, join is just one of the ways a string might have been created, and this could cause confusion.
This doc was originally written in the middle of Terraform v0.12
development while some refactoring was already in progress. Here we update
those parts to refer to where the relevant functionality finally landed,
and also update some things that we did not anticipate changing at the
time but ended up having to be changed during the v0.12 development
anyway.
For a while now we've been gathering some codebase-level docs that felt
out-of-place on the main Terraform website (since they are about the
implementation, not usage) but we had no existing suitable place to put
them.
In order to make this information more available (and, hopefully, more
likely to stay up-to-date as we change things), here we'll establish the
"docs" directory as a place to keep documentation aimed at those who are
working on code changes to the Terraform Core codebase.
User-oriented docs should never appear in this directory. The Terraform
website is always the better place for those. The set of docs here is
rudimentary to start and we'll see if it makes sense to expand and
reorganize it over time based on the experience with having these initial
docs available.
James Bardin